Improvement in keys for locks



WQM. GRISOOM. Key for Look. I

No.197,847. Paten ted Dec. 4,1877.

N-PETERS, PNDTO-LITHOGRAPHER. WASHINGTON. D C.

UNITED STATES PATENT OFFICE.

WILLIAM M. GRISOOM, OF READING, PENITSYLVANIA.

IMPROVEMENT IN KEYS FOR LOCKS.

Specification forming part of Letters Patent No. 197,847, dated December 4, 1877; application filed February 19, 1877.

To all whom it may concern Be it known that I, WILLIAM M. GRIsooM, of Reading, Pennsylvania, have invented a new and useful Improvement in Keys for Locks, of which the following is a specifica tion:

v, My invention relates to that class of keys which are made in two parts rigidly secured together, and the object of my invention is to construct a light and strong key of this character. This object I attain in the manner which I will now proceed to describe, reference being had to the accompanying drawings, in which Figure 1 is a perspective View of my im proved key; Fig. 2, a perspective view of the same with the parts of which it is composed separated from each other; and Figs. 3 and 4, a sectional plan and vertical section respectively of part of the key drawn to an enlarged scale.

The key is composed of two parts, A and B,

v the part A comprising the bow to and shank b,

and being composed of a piece of sheet metal,

' preferably of sheet-steel, and the part B, comprising the stem 0 and bit d, being of castbrass or other suitable metal.

The shank b is reduced in width at the front end, so as to form a projection, e, and the edges of this projection are recessed or nicked, in order to produce a number of barbs pointing rearward.

In the rear portion of the stem 0 is formed a slot, f, and in the body of the stem is a central opening, 1, the width of the slot being equal to the thickness 'of the shank b, and the size of the opening 6 being slightly less than that of the projection e of the shank. When the end of the shank is forcibly driven into the stem the projection e enters the opening i, and

.the end of the shank-body is adapted to aslot,

f, a pin, m, being then passed through the stem and shank, as shown.

There are then three obstacles to the separation of the two parts of the key: first, the pin a; second, the tight fit of the projection e Within the opening 41; and, third, the barbs on said projection, which bite into the softer metal of which the stem is composed. Additional security may be insured by subjecting the stem to the action of a suitable press after the end of the shank has been inserted.

The above-described key is much lighter and cheaper than one cast entirely of brass or other metal, and is at the same time as strong, or nearly as strong, as a solid key.

I do not desire to claim, broadly, a key made in two parts rigidly secured together; but

I claim as my invention 1. The combination of a key-stem having an opening, 6, with a sheet-metal shank having a notched or barbed projection, e, substantially as set forth.

2. The combination of the stem 0, having a recess, f, and opening 6, and the sheet-metal shank b, having a projection, 0, either notched or plain, with the transverse pin m, as described.

I In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

WILLIAM M. GRISGOM.

Witnesses:

HERMANN Monssnnn, HARRY SMITH. 

